That is ridiculous, people need to clean up after themselves in a buffett situation, whether it's a free buffet or a swanky lounge (where they encourage you to leave it but I never do).
That said and with NY's "its not my job attitude" I can easily see someone getting to work late one morning, the garbage pails piling up, someone decides to leave their crap behind and others start quickly copying that behavior. Garbage attracts other garbage, see Alice's Restaurant.
And I agree, better to let someone know at the property rather than complain to strangers on the internet but misery does like company. Perhaps this was a one off? Better to complain on morning #1 and let the world know on morning #2 if it continued.
Lifts are always a problem in NYC although it doesn't make it right.